Evaluation of the ethanolic ultrasound-assisted extraction from clove (Syzygium aromaticum) leaves and chemical characterization of the extracts.

In this study, clove leaves (Syzygium aromaticum) were subjected to ultrasound-assisted extraction (UAE) with ethanol as the solvent, following a central composite design to evaluate the effects of time, amplitude, solvent/sample ratio, and temperature on the yield, eugenol content, and antioxidant capacity of the extracts. The results were compared with those obtained using the conventional method of maceration (ME). The optimum conditions for extract yield were achieved with an extraction time of 25 min,amplitude of 85%, solvent/sample ratio of 35 mL g-1, and temperature of 70 °C, and the result (14.63 wt%) was three times higher than that of conventional extraction. Eugenol was detected in the extracts obtained by both methods, with the highest yield of 2.94 g eugenol kg leaves-1obtained in the UAE method, while the ME method achieved 1.36 g eugenol kg leaves-1.In general, the extracts exhibited high antioxidant capacities.

Production of a synbiotic composed of galacto-oligosaccharides and Saccharomyces boulardii using enzymatic-fermentative method.

Motivated by the search for healthy alimentation and sustainable technological processes, this study aimed to produce a synbiotic composed of the prebiotic galacto-oligosaccharides (GOS) and the probiotic yeast Saccharomyces boulardii, simultaneously, using cheese whey permeate as substrate by enzymatic-fermentative method. A central composite rotatable design with center point was used to evaluate the influence of temperature and enzyme concentration in the GOS and S. boulardii production. The best condition to obtain the prebiotic was at 32 °C and enzyme concentration of 0.175% (w/w), providing 56.84 g L-1 of GOS concentration and Ln(3.59) 107 viable cells mL-1 of S. boulardii production. However, the condition that would favor the simultaneous production of GOS and S. boulardii studied through desirability function is 29.5 °C and 0.14% (w/w) of enzyme concentration. The simultaneous enzymatic-fermentative method showed promising results considering industrial application and can be easily incorporated into dairy production lines as functional food.